Failing heart valves can become calcified and stenotic. Valvuloplasty is a procedure that can break calcification and open up heart valves. With the advent of percutaneous transcatheter heart valve replacement, the importance of valvuloplasty devices and procedures may increase, since a valvuloplasty procedure may be required to facilitate the proper placement and/or expansion of a percutaneously delivered valve. Typically the stenosed aortic valve would need to be opened using a procedure such as a balloon aortic valvuloplasty, prior to insertion of a catheter device and deployment of the replacement heart valve. A balloon opens the valve leaflets wider by a crushing action and cracks calcium deposits, making the leaflets more flexible.
During balloon aortic valvuloplasty, the aortic valve is blocked and a large pressure is created by the left ventricle during systole, and there are several drawbacks to prior art balloon-based valvuloplasty devices as a result of the pressure gradient between the aorta and the ventricle. Rapid pacing of the heart in order to lower the pressure gradient, but such rapid pacing of the heart has risks for the patient. Another problem associated with prior art balloon-based valvuloplasty devices is the tendency of the valvuloplasty balloon to slip out of the stenotic area during the valvuloplasty procedure. Such slippage may, for example, arise as a result of the pressures exerted on the device by blood ejected from the beating heart, or as a function of how the valvuloplasty device inflates.
In view of the drawbacks associated with previously known methods and apparatus for performing valvuloplasty, it would be desirable to provide a device that expands the valve area to remove the stenosis without creating a significant pressure gradient and without requiring pacing of the heart.
The art referred to and/or described above is not intended to constitute an admission that any patent, publication or other information referred to herein is “prior art” with respect to this invention. In addition, this section should not be construed to mean that a search has been made or that no other pertinent information as defined in 37 C.F.R. .sctn.1.56(a) exists.
All US patents and applications and all other published documents mentioned anywhere in this application are incorporated herein by reference in their entirety.
Without limiting the scope of the invention a brief summary of some of the claimed embodiments of the invention is set forth below. Additional details of the summarized embodiments of the invention and/or additional embodiments of the invention may be found in the Detailed Description of the Invention below.